Work holding device



July 20, 1937. I R. N. S ANDBERG I 2,087,266

WORK HOLDING DEVICE Filed NOV. 22, 1933 2 Sheets-Sheet l Fig.1.

July 20, 1937. R. 51. SANDBERG 2,087,266

WORK HOLDING DEVICE Filed No v. 22, 19s: 2 Sheets-ShetZ AWE/v TUE.

Patented July 20, 1937 WORK HOLDING DEVICE Robert N. Sandberg, Beverly, Mass, assignor to United Shoe Machinery Corporation, Paterson, N. J., a corporation of New Jersey Application November 22, 1933, Serial No. 699,201

2 Claims.

This invention relates to work-holding devices and is herein illustrated as embodied in a device for holding sheet material such as cloth in operative position upon the cutting bed of a ma- 5 chine for producing shoe part blanks from the material. I Y

In the cutting of shoe part blanks it is common practice to make use of a machine known as a clicking machine of the type illustrated in Let:

ters Patent of the United States No. 921,503,

granted May 11, 1909, upon an application filed in the name of A. Bates. This machine comprises a cutting bed and a presser arm swingable laterally over the bed and arranged for movement toward and away from the bed in producing a pressure-applying operation upon a freely movable die, located upon sheet material positioned on the bed, to cut blanks from the material. In connection with the cutting operations performed by'such a machineand particularly when it is desired to produce in a single operation a number of blanks from a plurality of layers of sheet material suchias cloth, as in producing linings for shoes, it is found desirable to clampthe material to the bed. This is desirable particularly when operating upon the ends of long strips of material, because the weight ofthe portions of the strips not directly supported by the bed is ordinarily sufficient to pull the ends of the strips off of the bed. Heretofore', various work-holding devices, commonly called cloth clamps, have been devised and have been utilized with varying degrees of success. One difiiculty experienced in the use of such device is that, in some instances, parts of thedevices project forwardly of the cutting bed in such a way as to interfere with the operator in his movements in locating the dies and in operating the machine. Further than this, considerable difficulty has been experienced in so 40 holding the material, particularly where such material comprises a plurality of layers, that the material will be firmly held during the cutting operation but also insuch manner that it can be shifted to a new position to expose fresh surfaces of the material to operation of the machine.

In view of all this, it is an object of the invention to provide a novel work-holding device which erably, and as shown, the apron is inclined relatively to the work-supporting surface of the bed and the arm is mounted for movement about an axis parallel to the surface of the bed and has a curved surface adapted to cooperate with the 5 inclined apron to clamp the Work. The arm is effective to exert pressure upon one or upon a plurality of layers of material to hold such material in place on the cutting bed but, at the same time, will permit the movement of the material when desired.

Other objects and features of the invention will be apparent from the following detailed descrip-tion when taken in connection with the accompanying drawings and will be pointed out in the claims. I

In the drawings,

Fig. 1 is a perspective View of a portion of a clicking machine embodying one form of the novel work-holding device; and 20 Figs. 2 and 3 are side and end views, respec tively, of the mounting for the apron and arms.

As shown in the drawings, the work-holding device is attached to the bed of a clicking machine which comprises a frame it having a cutting block support l2, a cutting block 14 and a presser arm 16 adapted for lateral movement over the block l4 about the axis of its supporting post l8 and arranged for movement toward and away from the block I 4 in applying pressure to work such as sheet material 20 positioned upon the block.

As shown, the sheet material 29 may comprise a plurality of layers of cloth suitable for the production of linings for shoes. This material usually comes in long sheets which may be carried in a roll below the bed l2, the ends of the sheets being brought up over the side of the block [4 and located upon the upper surface thereof in position to be operated upon by the presser arm l6. As successive portions of the material have been operatedupon toproduce blanks, for example, by means of freely movable cutting dies, fresh portions of the material'are drawn up over the side of the cutting block and located on the upper surface thereof.

The device as herein shown is adapted to hold the material upon the upper surface of the cutting block. To this end the device comprises an apron 22 and cooperating arms 24 adapted to grip and hold the material 20 along the side of the block M.

The apron 22 preferably comprises a wooden board having slots 26 in the ends thereof in which are positioned bolts 28 operative to secure the 55 Q thereof.

' lar slot 46.

prises a spring 58 one end of which is secured to Y to the forward edge of the cutting block it.

apron to brackets 30 which, in turn, are secured to the frame of the machine. The brackets 30, and their associated structure as well as the arms 24 at opposite sides of the machine are similar, and consequently, it will be sufficient to describe the structure shown at the right side only of the machine, (Fig. 1). Each of the brackets 30 is provided with an inclined face 32 against which the apron 22 is positioned so that the apron is held (asshown in Fig. 2) at an inclination of about 15- to the vertical, slopes rearwardly and upwardly toward the forward edge of the cutting block l4, and extends along the forward side The bracket 30 is provided with a slot 34 through which passes abolt 35 for securing the bracket to a second bracket 38 having asimi The bracket 38 in turn is secured to the bed i2 by bolts 62 extending through an elongated slot M in the bracket 38. The slot M provides for adjustment of brackets 39 and 38 toward and from the front of the cutting block l4 and the slots 3 and 49 provide for adjustment of the bracket 39 and, consequently, of the apron 22 heightwise of the cutting block i4.

Each of the arms 24 comprises a rod mounted for movement along a plane which extends at an acute angle tothe face of the apron and parallel To this end, each arm has a supporting portion 66 extending at right angles to the-body portion of the arm and loosely mounted in spacedrears or bearings 48 upon the bracket 30. To provide for adjustment of the arms 24 axially of the portion 46, that is; toward and from the apron, to accom-' modate wide variations in the thickness of material located between the arms and the apron, the portion 46 is provided with a flat surface 53 which is engaged by a set screw 52 borne by a collar 54 surrounding the portion 45 and positioned between the ears 48. The width of the collar is less than the distance between the ears so that a limited amount'of axial movementof the armportion 46 is permitted without releasing the set screw 52. a

Each of the arms 2!! has at its end a curved projection 56 adapted to engage the upper sur- 'The curved surfaces of' the projections make it possible for the arms to accommodate themselves to different thicknesses of material, the position of the areas of contact varying with the thickness of the material.

In order tohold the arms against thematerial in engagement with the apron with sufficient pressure to maintain the material in position there is provided mechanism for applying pressure to each of the arms. This mechanism coma pin 60 on the bracket 30 and the other end of which is secured to a pin 62 carried by an arm 64 mounted upon the end of the rodportion 45. The arm 64 is secured in position on the arm portion 16 by a set screw 66 which engages a fiat surface 68 on the portion 46. When the arm 24 at the, right ofFig. 1 is rotated into horizontal position such as that shown in Figs. 1 and 2, the

pin 62'will be located inwardly of a line between the pin 60 and the axis of the portion 46 with the result that the force of the spring 58 will act in a direction to rotate the portion 46 counterclockwise (in Fig. 1) to force the arm 24 and its projection 56 in a downward direction in which case the projection 56 will clamp the work against theapron 22. When the arm 24 is moved into inoperative position, that is, to a substantially vertical position, the pin 62 will be located so that the spring 58 extends along a line outside of the axis of the member 55 with the result that 'themember 45 will be rotated in a clockwise direction (Fig. 3) and the arm 24 will be held in inoperative position. To limit movement of the arm 24 the arm 64 is provided with lugs and 12 which are adapted to engage, respectively, oppositesurfaces 14 and IBM a lug 18 on the bracket 30.

In the operation of the device the end of the work such as a plurality of layers of cloth is placed upon the upper surface of the cutting block it and the arms 24 are rotated from their inoperative substantially vertical positions to substantially horizontal positions illustrated in Fig. l, the springs 38 forcing the arms 24 downwardly with the result that the curved surfaces of the projections 56 will cooperate with the inclined face of the apron 22 to clamp the material in position. When it is desired to place a fresh surface of the work upon the block M the material is pulled back over the block which is possible because of the fact that. friction between the surface of the material and the surfaces of the projections 56 will tend to move the arms 24 upwardly to release the pressure exerted by them.. The springs 58 will cause the projections 55 again to grip the material in its new, position. When new material is to be positioned upon the cutting block the arms 24 can be rotated upwardly and outwardly, and will be heldin inoperative position by the springs 58. 1

Thus it will'be seen that the invention provides a comparatively simple device for effectively holding work in position upon its supporting bed or cutting block and at the same time has eliminated any necessity for mechanism which will interfere with the operator in his carrying out operations upon. the material.

Having described my invention, what I claim as new anddesire to secure by Letters Patent of the United States is:

a work-engaging face, an arm pivotally mounted upon the frame and having a free end portion arranged for movement along and toward said work-engaging face substantially in a plane oblique thereto into position to wedge between the end portion of the arm and the support work located upon the support.

ROBERT N. SANDBERG. 

